30 Bulletin 1356, U. S. Department of Agriculture 
April are at a disadvantage in competition with this weed. On 
account of its quick germination at comparatively low temperatures, 
red rice makes a good growth before the cultivated varieties have 
emerged. If the sown stand is not completely destroyed, the sur- 
viving plants produce only a very small yield. A 25 per cent pro- 
duction of white rice is not unusual in a field that is badly infested 
with red rice. 
The presence of red rice also affects the quality of the white rice. 
Rough rice containing red rice is graded very low for milling pur- 
poses, and the price is materially reduced. Rough rice containing 
red rice should never be used for seed. 
The persistency of red rice as a weed is due very largely to the 
shattering of approximately 60 per cent of its seed by maturity. 
Without prompt and continuous control measures, this weed may 
take possession of a field within three seasons. Tne viability of the 
red-rice seed further complicates the control problem. This seed 
may remain in the ground in a viable state for several years and will 
germinate only when it is brought near the surface by plowing and 
other tillage operations. 
On many farms in southwestern Louisiana where there is a heavy 
infestation of red rice and other weeds, a part of the acreage usually 
is left uncultivated and pastured for the purpose of cleaning the 
land. This method is not effective, because the number of available 
cattle is seldom large enough to keep down weed growth. In addi- 
tion, there is always a quantity of seed of red rice lying too deeply 
in the soil to germinate until the land is again prepared for sowing 
the rice crop. 
In the early winter of 1910-11 one-fourth of an acre of land was 
plowed on the Rice Experiment Station to determine the viability 
of self-sown red-rice seed. The land was so foul with red rice in 
the season of 1910 that it made only a 10 per cent production of white 
rice. This plat was disked and harrowed the following spring until 
a good seed bed was obtained. Seed, however, was not sown upon 
it. A perfect stand of red rice was obtained. This growth was 
mowed when the plants were from 6 to 8 inches high and often 
enough thereafter to keep the plants from flowering and setting 
seed. The land remained in sod for four years and was mowed 
each year during the growing season as often as was necessary to 
prevent growth and seed production. In the winter of 1914-15 
the land again was plowed and in the following spring was disked 
and harrowed. Again seed was not sown. The resulting stand of 
red rice was even and uniform and was equal to the stand usually 
obtained b}^ broadcasting seed at the rate of 60 pounds per acre. 
Red rice, therefore, will remain in the ground for at least four years 
without losing its viability. 
After the first year mowing had little effect on the control of red 
rice, because very few seeds of this weed germinated. The greater 
part of the growth on the plat consisted of other weeds. This 
growth would have furnished a certain amount of pasture, but was 
of such character that a large acreage of it would have been required 
to support a small number of cattle. On account of the small 
revenue that would be derived from pasturing a weedy rice field, this 
method of control is expensive and also ineffective in eradicating 
red rice. 
